Contactor.



D. E. GRAY. com/amok.

APPLICATION FILED FEB. 12. 1917.

1,299,457. Patnted Apr. 8,1919.

a i I UNITED STATES PATENT OFFICE.

DAVID GIbAY, OF CHICAGO, ILLINOIS, ASSIGNOR TO RAILWAY UTILITY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

CONTACTOB.

Application filed February 12, 1917. $erial No: 148,280.

To all whom it may concern 7 Be it known that I, DAVID E. GRAY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Contactors, of which 0 tion of a panel with my improved contactor the fol, win isa specification.

Devices 0 the class to which my invention belongs are commonly employed for the purpose of opening and closing circuits carrying relatively heavy currents. One of the difficulties which has been encountered in such apparatus is that, owing to the extra current which is caused by the making and breaking of the. circuit, arcs are formed 7 which tend to waste and destroy the contacts andalso by incipient fusion of the surfaces cause the contacts to stick or freeze together. Among the remedies which have been adopted to obviate these disadvantages is to so construct the mechanism for operating the movable element of the contactor as to cause the movable contact to engage the stationary contact with a relative wiping or rolling motion whereby sticking is avoided and to employ two pairs of contacts, one of which 1 pairs carries the normal current after the make and break currents, thus relieving the contactor is closed and the other of which pairs of contacts is closed slightly before and opened slightly after the first said pair of contacts so that it carries the destructive first said pair of contacts in this respect .so that the members thereof are but little corroded or damaged and thus form a suitable connection for the main current.

,7 My invention relates to acontactor which embodies the above mentioned features for securing a satisfactory closure of a heavy current circuit and has for its ob] ect the provision of simple and eifectlve means for the purpose comprising principal and auxiliary ding part of this application I have described pairs of contacts and mechanism for operating the same so that the main'contacts are closed after the auxiliary contacts and' opened before the same, the construction be ing such that the contacts are given a relative rolling or wiping action to avoid sticking.

In the drawing accompanying and 'formin detail a preferred form of my device but it is to be understood that the specific disclosure is for the purpose of'exemplification' only, the scope of the invention being de- Specification of Letters Patent.

' Patented Apr. 8, 1919.

relinquishing or abandoning anyportion or feature thereof.

The drawing represents in elevation a secapplied thereto. The section of panel 1 is .as 'usual of insulating material and has mounted thereon the mechanism constituting my improved form of cont-actor comprising a pair of stationary contacts 2, 3, a pair of movable contacts 4, 5, a blow' out c011 6, an electromagnet 7 and terminals 8, 9. The statlonary contacts 2,.3 are mounted in' a casing 10 of insulated material, which comprises a cover plate'll, walls 12, 13 and spac ing blocks 14, 15, allsecured to the panel or support by screws 16, 17 The casing is open at its ends and the arms carrying the movable contacts 4, 5 extend into the open end of the casing so that the contacts are all of them always inclosed by the casing. The station- 19, 20, respectively to an intermediate block 21 of metal which in turn is secured by the screws 22, 23 to the panel and a heavy wire 24 leading fromthe stationary contacts is formed into the blow-out coil 6 between the end plates 25 and connected to the terminal 8. The latter is split or kerfed to receive the resilient folded connector 26 secured to the end of conductor 27 the outside member of the terminal being recessed as at 28 to accommodate the head of a screw 29 by which the connector is secured to the terminal. It

will be understood that the connector is ,minal 9 which is or may be substantially similar to terminal 8 in so far as the provision for connecting it to the electric circuit is concerned. The terminal 9 is mounted upon metallic plate 32 which also supports an inner endof the arm 35 at 40, The arms34 and 39 are formed with cars 41, 42 between which is compressed a coiled spring 43 which forces the arm 39 into contact with arm 35 and the latter into contact with the stop 38 upon arm 34, as shown in 'the drawing. A

wire 44 connects the terminal 9 with the arm 35, the other end of the-flexible wire being connected by a terminal 45 to said arm.

In the form of deviceshown in the drawing the switch is operated by the electromagnet 7, the coreof which is bolted to an iron bracket47 which in turn is bolted to a support 48 secured upon the panel. An arm 49 is pivoted at 50 to the support and car-- ries the armature 51 for cooperating with the expanded pole piece 52 and at, its outer end 53 is pivoted to a link member 54 whose other end is pivoted to the arm 34, at 37. The link 54 is formed in three sections, the intermediate of which 55 is of insulating material so that the magnetic field is free from currents. The arm 49 is extended beyond its pivotal point 50 into a tail 56 which co5perates with a stop 57 upon the support 48 for limiting the movement of the arm in that 'direction. The electromagnet may be furnished with current from any suitable source to the terminals 58 and 59.

Obviously when an energizing current is sent through the electromagnet 7 it attracts its armature forming a closed magnetic circuit comprising; the core of the magnet,

bracket 47 and armature 51. When the magnet attracts its armature the arm 49 through a the link 54 throws the contactor to closed the contact 3 there being no relative move ment between the arms .34, 35 and 39 up to this point. The further closing movement of the arm 34, however, causes the arm 39 which can move no further tocompress the spring 43 until the main movable contact 5 is in engagement with the stationary movable contact 2, this movement of the arm 39 relative to the arm 34 causing the movable auxiliary contact 4 to roll or wip along the surface of the contact 3, thus avoiding sticking or freezing of the contact. When the main contact 5 engages the contact 2 the high tension current caused by the closing of the circuit has passed so that there isno arcing between these con a The construction is such, however, that the main The main contact 5'is contacts 2,5 are in engagement sli htly before the arm 34 completes its movement so that the final movement of said arm "is accompanied by a relative movement of the arm 35 about its pivot 37 compressing the spring 43. Thus a slight wiping movement is had between the mam contacts 2 and 5 Y) which serves the purpose of keep-mg their surfaoesclean and in good condition. The

single spring 43 thus serves to resist the,

movements of arms 35 and 39 relative to the.

arm 34 and provides spring pressure 'under which the wiping action of contacts 3, 4 and to and carrying the mam movable contact, a I

second contact arm pivoted to the first said contact arm andcarrying the auxiliary movable contaqt, the pivots of the three said arms being parallel, and yielding means fornormally maintaining the main arm and said contact arms in fixed relation to each other and permitting a wiping action between the pairs of contacts as the switch closes.

2. In a device of the class described, a

stationary main contact, a stationary auxiliary contact, means for connecting said contacts to a source-of current, a movable mam contact, a movable aux1l1ary contact,

-means for connecting said movable contacts to the source of current, a main arm, means for swlnglng the same, a contact arm pivoted to said main arm and carrying the main movable contact, a second contact arm pivoted to the first said contact arm and car ry1ng the. auxiliary movable contact the pivots of the three said arms being parallel, abutments on said main arm and second contact arm, and a spring compressed .be-

tween said abutments and yieldingly hold-- mg the first said contact arm in fixed rela- 7 tion to the main arm and the second said contact arm in fixed relation to the first said contact arm. a

3. In a device of the class described, a statlon-ary main contact, a stationary aux- 1l1ary contact in close relation thereto, means for connecting said contacts to one side of a source of electrical energy, a main arm plvoted to a stationary support, a first contact arm pivotedto the main arm and hav- 1ng a llmited movement with respect thereto, an auxiliary contact arm pivoted to the first said contact arm and extending beyond the same, said first and auxiliary contact arms carrying contacts to engage respectlvely the stationary main contact and the stationary auxiliary contact and resilient means for normally maintaining the several stationary main contact, a stationary auxiliary contact, a main arm, a first contact arm pivoted to the main arm, an auxiliary contact arm pivoted to the first contact arm, the pivots of the arms all being parallel, an

* 10 extension 41 on the main arm, a spring between said extension and the auxiliary contact arm for maintaining the last mentioned arm yieldingly in fixed relation to the first mentioned contact arm,. and the latter in fixed relation to the main arm, the construction being such that as the switch closes the spring yields to permit a Wiping action between the members of the respective pairs of contacts.

DAVID E. GRAY. I 

